Improvement in burglar-alarms



l preferably hollow, so as to be light.

UNITED STATES PATENT OFFICE.

HARRY GILL, OF NEW YORK, N. Y.

IMPROVEMENT IN BURGLAR-ALARMS.

Specification forming part of Letters Patent N o. 184,773, dated November 28, 1876; application filed September 27, 1876.

To all whom it may concern:

Be it known that I, HARRY GILL, ofthe city and State of New York, have invented an Improvement in Burglar-Alarms, of which the following is a specification:

Burglar-alarms have been made with a nipple for a percussion-cap and a spring-hammer, that explodes the same if an attempt is made to open the door or window with which it is connected.

My invention is in the class of alarms aforesaid; and consists in the combination, with the spring-hammer and nipple, of a sliding wedge-catch, which serves a threefold purpose: it catches the hammer when the alarm is cocked for use, -it is the device that is moved by the door to set oiil the alarm, and it serves as a block to prevent the door being openr-d.

In the drawing, Figure 1 is a side view, partially in section, ofthe alarm as set for use;

and Fig. 2 is a plan ofthe same.

The base a is in the form of a Wedge, and At the thicker4 end are the spurs or prongs b, that enter the carpet or oor, and prevent the alarm sliding when inserted with the point of the wedge beneath the door. Upon the base a is the nipple d for a detonating-cap, and the fulcrulmv-standard c for the hammer f. The contractile springA g, between f and a, serves t0 re the cap when the tail h ofthe hammer is liberated from the catch i upon the sliding wedge l. lThis wedge is preferably hollow, for lightness, and connected, by the screws 0, to the base a, said screws going through slots, so that the wedge will move easily upon the base a, if the door is pressed against it, thereby unlatching the hammer-tail, and allowing the hammer to explode the cap. This wedgecatch will prevent the door being swung open, even if the alarm should fail to frighten away robbers, the Wedge acting as a block beneath the door.

This alarm, although especially adapted to l HARRY GILL. Witnesses:

GEO. D. WALKER, GHAs. H. SMITH. 

